// user's functions

function change_scroll_photos(img)  
{  
var tmp=new Image 
var maxsize=400  
tmp.src=img  
var wdth=tmp.width  
var hght=tmp.height 
if (wdth>maxsize)  
  { 
   var coeff=Math.max(wdth, hght) 
         coeff=coeff/maxsize 
    wdth=wdth/coeff    
    hght=hght/coeff  
   } 
document.getElementById('middle_pict').src = img;
document.getElementById('middle_pict').width = wdth;
document.getElementById('middle_pict').height = hght;

return false;
}